Perhaps you should try some spelling variations:
nhanh thai » nhanh thi, nhanh thanh, nhanh thang
hoc thiet » hoc thieu, hoc thuyet, toc thieu
hanh thau » thanh thao, thanh chau, hanh tu
dung cong » dung trong
cong dan » cong san, cong tan, huong dan
dan chan » dan gian, dan ca, van chat
chan cau » phan cau, can cau, chinh cau

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thiet) OR (hoc hien)) tach - ((hanh thau) OR (nhanh thai)) xay dung cong dan chan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thiet) or (hoc hien)) tach - ((hanh thau) OR (nhanh thai)) xay dung cong dan chan cau~".
• Adding a wildcard symbol may retrieve word variants: ((hoc thiet) or (hoc hien)) tach - ((hanh thau) OR (nhanh thai)) xay dung cong dan chan cau*.